Social taboos originally related to religion and ritual, and Philip Thody contrasts our contemporary bodily taboos with the ritual taboos of tribal cultures: "In our society, that of the industrialised West, the word 'taboo' has lost almost all its magical and religious associations" (1997).

Robustness can be regarded as the ability of the SCC mixture to maintain both the fresh properties and composition pre- and post-casting of one batch or successive batches, due to the composition of the mixture and due to some small changes in the contents of the ingredients of the mixture. 143-153, in Self-Compacting Concrete, Proceedings, 3rd Intern. By contrast, neither silica fume nor most types of fly ash can be considered as density modifiers. Sakata et al.[i] reported that SCC made with low w:p ratio of 0.33 (powder containing limestone filler), the incorporation of a small concentration of welan gum of 50 g/m3 can reduce the variability in slump flow of SCC due to changes in cement Blaine (318 to 342 m2/kg), fineness modulus of sand (2.08 to 3.06), and temperature of fresh concrete (10 to 30°C). The authors concluded that the slump flow value tends to prominently decrease with an increase in natural moisture content of fine aggregate for mixtures with 0.35 w:c ratio as opposed to 0.5 w:c ratio.